1. Field of the Invention
The present invention relates to an abnormality monitoring system for an electronic component to and from which signals related to power supply and drive control is input and output through a harness member, and an image forming apparatus.
2. Description of the Related Art
In a recent electrophotographic image forming apparatus, its structure and control system have been complicated because of the speed-up of functions, high resolution, downsizing of the apparatus, or the like. In particular, the number of electronic components installed, such as various types of drive motors for driving internal drive units, is increased, and drive control with complicated timing and the like becomes necessary for the electronic components.
When the drives of such a plurality of drive motors are simultaneously controlled and if a single control circuit (CPU) is used for drive control, an expensive and high-precision control circuit has to be used.
Therefore, in an image forming apparatus requiring complicated drive control, as illustrated in FIG. 6, for example, a control board with a control circuit is divided into a control board 1A for an image forming system and a control board 1B for a conveying system, both of which drive control the drive motors M1 to M6 in a unit manner.
For the drive motors M1 to M6 such as brushless DC motors as the electronic components, signals need to be simultaneously transmitted from the control board 1A to the drive motors M1 to M3 or from the control board 1B to the drive motors M4 to M6. Therefore, the control board 1A or 1B and the drive motors M1 to M6 are electrically connected to each other through respective harness members H1 to H6. In addition, the harness members H1 to H6 have to be routed along complicated paths inside the apparatus.
An image forming apparatus that monitors a fan lock signal and stops the fan when the fan is locked has been known (see, for example, Japanese Laid-open Patent Publication No. 2008-047996)
However, the image forming apparatus described in Japanese Laid-open Patent Publication No. 2008-047996 is designed only to detect a failure of the fan being an object to be controlled, and therefore abnormality of the harness members H1 to H6 as illustrated in FIG. 6 is not considered.
There is a need to provide an abnormality monitoring system capable of determining an abnormality of a harness member connecting an electronic component and a signal device and an image forming apparatus.